Embedded Intelligent Objects in Food Logistics Technical Limits of Local Decision Making

Abstract

The efficiency of transport monitoring systems in the supply chain of food products can be improved by autonomous control, which means that decentralized intelligent objects have the ability to process information, to render, and to execute decisions. In our example the supervision and data evaluation tasks are distributed in a network of wireless sensors as local decision platforms. The supervision network can also include semi-passive RFID tags. The application of such battery powered embedded devices is limited by the reliability and range of communication as well as by the required energy resources. Autonomous control helps to overcome the first restriction. Communication is reduced and the system is less dependent from unreliable network links, but the power required for calculation increases the total energy consumption. In this paper the communication limitation of passive UHF RFID and active wireless sensors were analyzed by laboratory experiments and field tests in sea containers. Several algorithms for local data evaluation by autonomous control were evaluated on typical target systems for wireless units. Calculation times and the resulting energy consumption were measured and compared with the energy that is required for communication.